The present invention relates to the dynamic braking of a transit vehicle, with a brake request P signal indicating the desired brake effort and with the receptivity of the power supply line determining how much regenerative dynamic braking energy is provided to the supply line and how much has to be dissipated in the dynamic braking resistors.
In an article entitled Propulsion Control For Passenger Trains Provides High Speed Service published in the Westinghouse Engineer for September 1970 at pages 143 to 149, there is discussed the operation of the P signal to establish the requested brake effort in the brake mode of operation.
In an article entitled Alternative Systems For Rapid Transit Propulsion and Electrical Braking published in the Westinghouse Engineer for March 1973 at pages 34 to 41, there is discussed the thyristor chopper operation for dynamic braking, with the generating motors providing output current that is either returned to the supply line or dissipated in a dynamic braking resistor by turning on the thyristor T5 shown in FIG. 3b of that article. The thyristor chopper is fast enough to match regenerated voltage to line voltage.